I don't wish the Tauthon project ill but I suspect people are underestimating how much work goes into maintaining Python 3. If the Tauthon project scope was limited to taking Python 2.7.X and doing bug fix only releases of it, I think it could be a successful project. Since they seem to be backporting features from the 3.X branch, I don't see them keeping up. Python 3 has too many users at this point. If you look at the Tauthon commit log, it seems clear they are being left behind.

There is another problem with trying to backport selected Python 3 features. How do you decide what gets backported? New features will introduce incompatibility. Even if the feature is forward compatible, you end up with code that will run on Tauthon 2.X but not on Tauthon 2.X-1. If it just a better Python 2, that's fine. When it is some 3rd kind of thing with a relatively tiny user base, who is going to use it?